基于SLAF-seq玉米高密度遗传连锁图谱构建与株型性状QTL定位

 株型直接决定生物产量、种植密度与籽粒产量，利用玉米高密度遗传连锁图谱解析株型相关性状的遗传机制，对选育理想株型玉米新品种具有重要意义。本研究利用SLAF-seq技术，依据玉米黄早四参考基因组信息，对昌7-2与PHB1M及其138个F_2：3家系高通量测序，开发高密度SNP的遗传图谱，并进行株型相关性状QTL定位。研究结果构建了一张总图距为1354.81 cM，标记间的平均距离为0.32 cM，标记数为4220个SLAF标签（7876个SNP）的高密度遗传图谱。在E1与E2两种密度下，对株高、穗位、叶片数、节间数、平均节间长进行QTL定位，共检测到10个QTL位点，其中，有7个PVE超过了10%。叶片数、穗位、节间数为主效QTL，ADD为负值，叶片数与节间数的减效等位基因来源于PHB1M，穗位的减效等位基因来源于昌7-2。叶片数与节间数在2个密度下均定位在8号染色体上，说明二者之间有着共同的遗传机制。与QTL关联的SLAF标记共有61个，其中，SLFA7305498和SLFA6717271为qLC-2-LG8与qIC-2-LG8共有标记。该研究将为玉米株型相关性状的标记辅助选择提供支撑。

Construction of high-density genetic linkage map of maize based on SIAF-seq and QTL mapping of plant architecture traits

The plant architecture directly determines the biological yield, the planting density and the grain yield. The genetic mechanisms of the plant architecture related traits are analyzed in this paper by using the high-density genetic linkage map of the maize. This map is of great significance for breeding new maize varieties of ideal plant type. To develop high-throughput SNP markers for the high quality map from Chang 7-2×PHB1M, and the map QTL of the plant type related traits, 2 parents and 138 individuals of their F_2:3 population are detected by the SLAF-seq technology. The results are used to construct a highdensity genetic map with a total distance of 1354.81 cM, an average distance of 0.32 cM between markers, and with 4220 SLAF (7876 SNPS) as markers. With the densities of E1 and E2, QTL is mapped for the plant height, the ear height, the leaf count, the internode count and the average internode length. A total of 10 QTLs are detected, and the PVE of 7 QTLs exceeds 10%. The leaf count, the ear height and the internode number are the major QTLs and the ADD is negative. The decreasing effect alleles of the leaf count and the internode count are from PHB1M, and the ear height is from Chang 7-2. The leaf count and the internode count are located on the chromosome 8 at both densities, showing that they have a common genetic mechanism. There are a total of 61 SLAF markers associated with the QTL, among which SLFA7305498 and SLFA6717271 are the common markers of qLC- 2-LG8 and qIC-2-LG8. This study provides a support for the marker-assisted selection of the plant architecture traits.